I don't like the fibreoptics or beads.

I like a wide, deep, square notch rear + square-topped front post/Sourdough in a combination that allows light to be seen on either side of the thick blade/post front. Fast and accurate up close and repeatably accurate out to 100m which is as far as I want to shoot using iron sights. I HATE beads as I cannot keep zero consistent; light coming from different directions changes the glare on the round face of the bead and consequently the zero shifts as well.

I like a dull, flat-topped, square notch rear + a dull, square-topped front post.

Here are a few. I cut and file them to zero.